Dell Inspiron 660s Intel Processor replacement/upgrades

I read somewhere (the Owner's Manual on pp. 59, 66) on Dell Inspiron 660s that I purchased in May that one can either replace the Processor chip/fan.  I do have a Intel Dual Core processor and all is good.  Is there a way that I can like upgrade the processor to like an Core i3?  I realize that it's a small computer and it would be impossible to expand things like an extra hard drive or a video card, but I wanted to know if changing the processor and the fan is possible.